1FEATURES
2• Fully Differential Amplification
• Available in Space-saving WQFN Package
• Ultra Low Current Shutdown Mode
• Can Drive Capacitive Loads up to 100pF
• Improved Pop & Click Circuitry Eliminates
Noises During Turn-on and Turn-off
Transitions
• 2.4 - 5.5V Operation
• No Output Coupling Capacitors, Snubber
Networks or Bootstrap Capacitors Required

APPLICATIONS
• Mobile Phones
• PDAs
• Portable Electronic Devices

KEY SPECIFICATIONS
• Improved PSRR at 217Hz 85dB(typ)
• Power Output at 5.0V @ 1% THD+N 1.1W(typ)
• Power Output at 3.3V @ 1% THD+N
400mW(typ)
• Shutdown Current 0.1μA(typ)

DESCRIPTION
The LM4923 is a fully differential audio power
amplifier primarily designed for demanding
applications in mobile phones and other portable
communication device applications. It is capable of
delivering 1.1 watt of continuous average power to an
8Ω BTL load with less than 1% distortion (THD+N) from a 5VDC power supply.
Boomer audio power amplifiers were designed
specifically to provide high quality output power with a
minimal amount of external components. The
LM4923 does not require output coupling capacitors
or bootstrap capacitors, and therefore is ideally suited
for mobile phone and other low voltage applications
where minimal power consumption is a primary
requirement.
The LM4923 features a low-power consumption
shutdown mode. To facilitate this, Shutdown may be
enabled by logic low. Additionally, the LM4923
features an internal thermal shutdown protection
mechanism.
The LM4923 contains advanced pop & click circuitry
which eliminates noises which would otherwise occur
during turn-on and turn-off transitions.